We can help you find a solution or connect you to technical support. This restores missing or corrupted Office components that affect search indexing. If a Microsoft 365 application such as Word or Excel isn't working correctly, sometimes restarting it will fix the problem. Download the tool from Microsoft and run the Outlook diagnostic to auto-detect server and account issues.

⃣ Reset Browser Cookies & Cache

If your admin enabled Modern Authentication (MFA), try disabling it temporarily via Azure Active Directory → Properties. Alternatively, generate an app-specific password if using Outlook 2016 or older. This resets your authentication cache and forces a fresh token request.

Microsoft 365 Apps Crashing After Update — Step-by-Step Repair Guide

• With Microsoft 365, you can designate several types of administrators who serve different functions.
• If your Microsoft 365 suite keeps crashing or you can’t recover lost files, reach out for expert help right away.
• This process replaces damaged core files without removing your data or customizations.
• You must have at least one subscription bought through Microsoft to access Microsoft support.
• Then, navigate to File → Options → Add-ins, and disable all non-Microsoft add-ins.
• Microsoft 365 Basic now comes with 100GB of cloud storage, secure photo and file storage, secure ad-free email, and technical support.

For iPhone users, reinstalling Outlook or updating to the latest iOS often resolves stuck sign-in loops instantly. Many users have both personal Microsoft accounts (e.g., Outlook stuck updating folders solution Outlook.com) and work/school Office 365 accounts. If both are signed in simultaneously, the system can confuse the authentication path.

? Fix Office 365 Login Issues on Mobile

21Vianet assigns a severity level to a case when it’s opened, based on an assessment of the issue type and customer impact. Examples of issue types and severity levels are shown in the following table. Authorized administrators can use the Microsoft 365 operated FixTechGuide Office 365 troubleshooting by 21Vianet portal to submit service requests online and access support telephone numbers.

Step 2 – Update Outlook and Office 365

Go to Settings → Windows Update and install all pending updates. Then open any Office app → File → Account → Update Options → Update Now to ensure both are synchronized. Go modern authentication troubleshooting to Control Panel → Programs and Features, select Microsoft 365, and click Change → Quick Repair.





Explore learning tools to collaborate on projects together and independently, all in one place. Create equitable learning environments that help students develop knowledge with familiar apps essential to both academic and future career success. If login issues are still persisting, our experts can assist you live via WhatsApp. We’ll walk you through step-by-step solutions for Office, Outlook, or Teams sign-in errors.